1. Field of the Invention
The present invention relates to a portable electronic device, and more specifically to a portable electronic device and its external keyboard.
2. Description of Related Art
In a conventional mobile phone, the existence of a keyboard of the mobile phone is a major issue for the screen size and the volume of the mobile phone. In recent years, a mobile phone having a “qwerty” keyboard (such as Palm and Blackberry) brings convenient operations to users, but the mobile phone is generally thicker and heavier or has a relatively smaller screen, which cannot be popular among customers. As the touch screen technology matures, present mobile phones tend to have a super thin design, and most mobile phones have omitted the keyboard by simply using the touch screen as an input interface. A typical example is Apple's iPhone. However, the mobile phones come with increasingly powerful functions, and become a portable recreation platform, and many manufacturers and content providers developed many games for mobile phones. Without a keyboard, it will be very difficult to play games or send mails from the mobile phones.